These bolts are the standard bolt, used in the vast majority of greenhouses. Easily removed and re-used. perfect for attaching shelf supports and brackets etc when assembling the greenhouse. Necessary accessories for building most greenhouses. Also a good replacement when the parts is damaged. Made of premium metal, , sturdy, hard, for long time use. Simply insert the bolt into the groove of the glazing bar and turns to lock securely in place when the nut is tightened., Manufacturer: PokFhgur